In the heart of the ITER fusion reactor, intense radiation will relentlessly batter the metal walls, potentially compromising their structural integrity. To prevent catastrophic failures, scientists are meticulously studying how radiation alters the properties of metals at the atomic level.

Using cutting-edge techniques, researchers at the University of California, Berkeley, are simulating the damaging effects of radiation by knocking individual atoms out of a metal lattice. By examining the resulting defects, they aim to gain a comprehensive understanding of the microscopic processes that contribute to radiation-induced material degradation.

"By understanding the detailed mechanisms of radiation damage at the atomic scale, we can develop strategies to mitigate their effects," explains Andrew Minor, a professor of nuclear engineering at UC Berkeley and the lead researcher on the project.

In their experiments, the team utilizes a focused beam of charged particles, such as helium ions, to bombard a thin foil of metal. Each ion collides with atoms in the metal lattice, transferring energy and potentially knocking them out of their positions.

To visualize the damage, the researchers employ a suite of advanced microscopy techniques, including transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). These techniques provide high-resolution images of the defects, revealing the location, size, and shape of the displaced atoms.

By carefully controlling the ion beam intensity and energy, the team can systematically study the effects of different radiation doses and types of ions. This allows them to identify the key factors that influence the formation and evolution of defects in the metal.

"We're particularly interested in understanding how defects interact with each other and how they collectively affect the overall properties of the material," says Minor.

The team's findings have implications for the design and development of materials that can withstand the harsh radiation environment of fusion reactors. By identifying the most radiation-resistant materials and understanding the underlying mechanisms of radiation damage, scientists can enhance the safety and efficiency of these promising energy sources.

This research is supported by the U.S. Department of Energy's Office of Fusion Energy Sciences and is conducted as part of the Berkeley Fusion Science Center.